Thermo-electric pile.



1 A. RITTERSHAIISSEN. THERMO ELECTRIC FILE. APPLICATION FILED JUNE a, 1908;

911 446, Patented Feb. 2, 1909.

? eno r nrrrERsHAUssEN, oreassat, cannery.

meremro-Emcmrcrm.

Specification of Letters Patent.

' Patented Feb. 2, 1909.

' applicationfiledJune,1908. SeriaINo. 431,591.

To all 'wltoai it m factgm Be it known that. I, AD L 'RITTERSHAUS- SEN, subject-of the'Emperor of Germany, re--,

siding at Cassel, tithe-Empire Jf-Germany, have invented certain new and "useful; Improvements in Therm)"- Electric P les, of which thefollowingisa Specification.

' There are known thermo electric piles; in

- which the heatinggandcooling surfaces are annular and 'concentric, so that a hollow cylinder is formed, the inside "of which shows exclusively heating surfaces and the outside exclusively "eooling surfaces. Such thermoelectric piles are; however, uneconomic,i

since considerable losses are produced, as neither the ohmic loss (that-1s the .loss proa duced by the conductivity resistance) a e the transmission of heat through theinterrial partsh-as been taken into consideration. My inventionrelates to improvements 111 such thermoelectric piles, whereby t-llQlI'USG-r ful ell'ec'tis considerably increased. j'l'The me tallic components of each couple consist each .of two coment'ric rings which are quite distinct and are connected together only by nar- {row or thin parts, the cross section of which dependsupon the required stability currenti'to be conducted through-them. The

and the several" components are not connected-with one another on their conta'ct faces by soldering-as usual, :but they, are combined a spe cialnewn1anner.) The therinoelectri.c pile so "coi'is'tructed is -mo'st advantageous, asv all, excessive Ol1-1]11G-'.2L11Cl calor c losses a're avo ded. The newconstruction also renders I it possible 'to-improve upon the manner of heating the pllefor obt annng a considerable my invention.

. parts throughout theseveral views.

The thermo-eleotric pile shown at Fig. 1 comprises a series of superposed couples each formed of two metallic components. Each '3. The two rings a andb are onit the arms f e ismade only so larg quired b'ycthe stability, of the l by the electric. current to e t ansmitted. through them, the ohmic and caloric losses being at 'theS-same-time taken intoconsidera- ,tion, they depending-upon thedcsired' maXi-fi component of the ,one electrically metal consists of an internal. ring a. and-an external ring which. r onnected-t th geth'er-by means of several thin hori gng l arms e, as is clearly shown at-Fi' 's." and nside and outside respectively-of the pile;

tive meta consists of. an internal ringcand ev Each com client of the other electric lly-lac j an external ring 11, which are connectedtgi 1 f.v

gether by means of several hin r adi al'iverti-- 'ongof cal arms f as is shown Thecross isareileprcp ar d-' mum useful ellect of the pilef .z'rhelatteris; obviously obtained when theloss' of heatfin i the ,transmism'on through the arms cia'ndzf plus the ohmic loss is made a The contact surface h between the proximate internal ringse and .c of any two components isnrthei drawing assumedto be the el'e'ctrically active "heating surface, and the contact surf-ace lc between the proximate external 1 rings d'and bJofany two components is'assumedto be-the electrically active cooling 1 surface. Preferably these two surfaces are made alike, that is to say, the product of theperiphery and of the height should be the same for the heating surface as well as for the cooling surface. losses of heat in the arms 2 and. f and alsoto prevent the direct radiation of heat from the heating surface It to the cooling surface la a bad heat-conductor gof any known kind is preferably inserted between the internal rings a c and the external rings d b and is made to fill up the space, see Fig. 1. 77

With the construction just described of. the thermo-electric pile the resulting contact surface at the heating surface h as well as at the cooling surface it will be very large, so thatthe resistance of the contact and thereby the ohmic loss will be, reduced. The

In order to avoid other losses causedby the transmission of heat I through the arms e and f and by the direct radiation of heat from theheatin-g surface 7L to the cooling surface It are-also reduced to a minimum. Further all other surfaces, to which any undesirable heat might be supplied or from which this heat might be carri'ed off, are avoided. The said contact surfaces are according to 1T1y' 1]1Ve11tl0Il still fiirther increased by provid ng the proin v mate rings with projections and recesses or grooves adapted toe'ngageieach other, so that in this manner Within the-same height:- a considerably greater contact surface is obtained than before without .at the same time increasing the other losses which are proportional to the said height. in Fig.8.

the said; projections and recesses or grooves are shown as formed by a fine and very deep screwthread. Thediameter and tlielheight of the electrically active heating'and coohng the theory of the conversion of heat into surfaces depend uponvthe stren th of the current passing through the coup e and can therefore be determined from the beginning.

.In Fig. 1 the diameter of the coolinglsurface it is double that of the heating surfaceh and therefore the height of the former is made only half that of the latter. Owing to the.

.horizontal arms a the total effective heatingsurface ofeach couple exposed to the action of the heating gases is of-course larger than theelectrically active heating surface 71, its

heightH being like the sum of the height IL, ofthe heating surface 7t plus the height of the arms e, see 1* ig. 3. Of the heat supplied to the effective heating surface of'the height H the larger art passes through the electrically active ieating surface it of the height H,,, while the rest passes through the arms e outwards.

1n the electrically active hcating' surface h of the height-l1 the heat is turned into electricity, when a drop of the temperature will take place in accordance with work. i

Iinake the height of the external rings b on .the outside of the pile about like that of the internal rings a on the inside ofthe pile, and consequently I make the height of each external ring 1) larger than that K of the cooling surface is, viz. like the sum Li -+K see Fig. 3. I connect the upper part of the I hei ht K in about its middle with the severa arms e. Then the heat passing through the arms 0 and forming a source of loss for the couple isdistributed over the cooling surface ofthe height K which adjoins the effective cooling surface of the height K so that the said heat can beat once carriedofl' by cooling the said surface of the height K and is prevented from "exercising any inj urious influence upon the electrically artive cooll irigs'urfaee is by heating the same.

I or

eight H can be turned into electricity, the rest of the same will (pass through the arms f and will be increase by the heat produced by the Joule and Peltier efi'ects, so that this sum of heat will require to be carried off from the'effective .cooling surface of the height K The proportion, in which the practical reasons-not all the heat" passing ,t irough the heating surface of the in was heights K and K stand, is determined by the ratio of the heat units to be carried off from' the two cooling surfaces.

I Thehcooling by air being objectionable,

since thespace at disposal? is too restricted,v

I prefer to cool the outside of the pile With K117913611. For this purpose I dispose the therino-electric pile sofar described: within the central tubular wall rot a cooling vessel 0, which maybe of any'known and-approved construction. This vessel C may be closed at the top, as shown, or it may be left' 'open,

and thecooling Water may be passed throu h it in any known-manner. For example t 1e cold water may; enter the vessel 0 at its bottom through. a 'tube 0 and circulate ifl l'flulld the internal wall twhilerising up- 7. wards, whereupon the warm water may carried off per unit of cooling surface is exceedingly small and very much less than that I which as a rule isiconsidered technical apparatus.

vl'ith the known thermo-electrie couples the components are combined either by permissiblev in soldering the. different metals on one an other or by casting onemetal'around the other one.. The latter method can be employed only in special cases, while the former method is in general use, but .it presents the following defect: There would be a layer of soldering material, between the two different metals, so that the electric current s ill necessarily have to pass through two contact surfaces, whereby of course the contact resistance is doubled. It would not do to connect the two metals by simply applying them to one'another, for example by screw big one metal into the other metal or by any other similar method, since the contact could not be made sufficiently intimate. It would then be impossible to procure an exact lit on all placesbetween the twonnetals, as it should be for keeping as low as possible the resistances of the transmission. 1 According to my invention the two metals are conneeted'together by any suitable. means but prefci ably by methods which produce a most intimate combination of the two metals without any noticeable space. Itis only with the aid of such a method that the increase of the contact surfaces can be utilized. When taking into consideration, that the resistance of transmission between thecomponents of a thermoelectric couple "orins means of the arms. "lt-isgobvious'toany one;

round internal'j'rings may draulic pressure, An 'o-.ther known; method may also be'employedfoi' obtainin'gfsimilar effects;

- Z in its'internal tapering and'closed end. A small hole m is provided in the cover n. This closing'of'the cavity of the pile in com binationwith the large contact surface of absolutely necessary to use a far greater only a' sniallfquantity of .fresh combustible versed in. the artpm wh'at manner'the elece trolysis may be employed-forconstructingscribed is provided with a terminalq U c 'known construction ;-and the ';-1ippermost couple with another terminal a". 'lhe-cylin- I 'oi." heating I employ the spent gases for heating surfaces of the pile.

an essential source of losses, it being in-vi versely prcportional'to thesize of the con: tact surface, itwill-be clear, that according to my invention this loss can be quite con siderably reduced. I 4

When employing the electrolysis f f'onepof any two proximate rings ofthe several mm;

by the electrolysis in any convenient order, and may be connected v'v'vith-one another by the thermo-electric' pile." -'When employing pressure, the external-rings intend be-heated.

lied to the latter, afte which they H owed to contract jbyzcooling ofi".. ,hOr they may be forced. on' the internal rings. by by t-tonne "oi the .cf ayi dricalcavity of. the pile is preferably closed bottoms and is provided with severalvholes the heating surfaces It permits it to heat the new therm'o-electric pile in a special and economical manner, as will be hereinafter described. v

. 'With the known thermo-electric piles it is.

quantity of cold air than is necessary forthe combustion, in order to reduce the temperature of combustion, so as to prevent the components having a low melting point from melting. In opposition to this manner heating the pile, since these gases possess a comparatively loW-tempcratureand I burn mixture whiclris suflicient' for reheating the spent gases, so as to utilize their heat to. theutmostfor heating the pile. The combustible mixture passing through the. heating pipe 11 and entering the nearly completely closed' chamber A through the holes Z is lighted and burns. The combustion is suflicient for reheating the spent gases. filling up the chamber A, in other Words it replaces the heat given oii by the spent gases to the Only an excess ofthe spent gases corresponding to the quantity of gases produced during the com bustion the fresh combustible mixture permitted to escape from the ehamberA through the hole m of the covera. The area-ofthe-hol es Z, in the tapering end of the heating pipe '1'; is'determined by the quantity of combustible mixture which is required "fon'reheating the spentgases up. to the de ponents-may be formed by electrolysisand the several rings in the pile may be produced I" siredytemperature. -'ll1 us the temperature offthefresh burned gases producedduring the-combustion is reduced by the spent gases and notby an excess of cold aira's hitherto.

Obviously a great saving incombustible mixture-is thereby gained,

" Where sopreferred, the spent creased from below upwards, and between gases may be utilized in the manner? diagrammatically {illu'strated'at Fig. 4'. That is to say,-the finternal diameter of the 'efiective' heating surfacesoftheseveral superposed-con les of .thei pile? is gradually and su'ccessiveyintheseveral couplesseparate-partitions nynfi I with heating pipes i -"i .'are inserted. I Then thecombustible' mixture; escaping hamme holes 'Z- of, the lowermost pipe ,I: ring its combustion reheat the spentgases injthe chamber within the lowermost couple-fzfor heating .the heating surface of the latter, whereupon; the spentjgases.pa'ss- Y ing upwards, through the hole. m"--in the first"ipartition n will be reheated bythe combustion of the combustible mixture escaping from. the holes .1 of the second heating pipe i spent gases will be thereby increased and for tlzisreason the chamber is made larger in diameter.

I After heating the heating surfaceof the second couple'thespent gases pass upwards through the hole m in the second partition 17. to be reheated by' the combustion of the combustible mixture escaping from the holes ingpipe i and so on. Of course *theareas 0f course the volume of the f Z of the 'third heatof the holes 1'1 Z of the several eating tubes 1' i. i .*\'ill be determined y the heat units which "are required for reheating the spent gases ln the several chambers."

The thermo-electric pile described may be varied in many respects without departing from the spirit of my invention.

Iclaim': I

1. A thermo-electric pile comprising a plurality of superposed annular couples, each couple formed oftwo components of different -metalsand'each component. consisting of two concentric cylindrical rings and arms between them, the ringsof the components of one active metal being in intimate contact with the proximate rings of the components of another activemetal and the product of the periphery and of the height of each contact surface in the roximate rings being substantiallyuniiorm t iroughout the pile.

2. A thermo-electric. pile comprising a plurality of superposed annular couples, eacn couple formed of two components of differw tt cut metals and each vcomponent'cqmsisting oi. two concentric cylindrical rings and 'arms, between them, the rings of each component of one active metal being approximately in the same plane. and in intimatecontactwith the proximate rings of two neighboring components of. another active metal," the re duct of the periphery andof tl1e- "l1eig-1t of each contact surface in the proximaterings being substantially uniform. throughout thevile. v i 1 3. A thermoelectric pile"compri sing.f'a plurality of super osed' annular couples, each couplerforme of two components of different metals and each component consisting ofttwo concentric cylindrical rings and armslaetween them, the internal ring of each component of one metal inclosing the internal ring of the next vcomponent of another metal, while the external ring of the former is inclosed by the external ring of the other next component of another metal, -all the proximate rin s being in intimate contact with one anat er and the product of the periphery and of the heighto each contact surface-being substantially uniform thr0ughout the pile.

4. In a thermo-electric pilefthe combination with a lurality of superposed annular couples, eaci couple formed of two comnot of the periphery and of the height of' each contact surface being substantially uniform throughout the pile, means for producing a relatlve difference of temperature F between the outside and the inside of the pile. 5. In a thermo-electric pile, the combinatlon with a plurality of superposed annular couples, each couple formed of two compo-- nents of different metals and each component consisting of two concentric cylindrical rings and arms between them, the internal ring of each component of one metal inclosing the internal ring of the next component of another metal, while the external ring of the former is inclosed by the externalring of the other next component of another metal, all the proximate rings being in intimate contact with one another and the product of the periphery and of the height of each contact surface being substantially uniform throughout the pile, while the rings on the inside and outside of the pile respectively have the same height and are arranged to provide a narrow space between adjacent superposed couples, means for producing a relative difference of temperature between the outside and the inside of the pile. v

;,l. A thermo-electric pile comprising a plurality of superposed couples, each couple 'orm'ed, of two components of different metalsf-and each component consisting of twoconcentriccylindrical' rings and arms between them, the rings of the components of one active metal being in intimate contact with" the proximate ring of the other active metal.

'- 7. Afithernio-elect'ric pile comprising a 'alurality of superposed couples, each couple i'ormed of two components of different metals and each component consisting of two concentric cylindrical-rings and arms between themfthe rings. of the 'componentsol one active metal-being in intimate contact with tithe proximate ring of the other active meta the proximate faces of the respective parts beirig'provided with projeetio and recesses t'o inter-engage one another or increasing the contact surface.\ y

'8. Ina 'thermo-electrie pile, the com-,

bination with a )lurality' of superposed annular couples, one 1 couple formed of two coinponents of dilicrent metals and eaclr component consisting of two concentric cyhnr,

drical rings and arms between them, the rings of the components of one active metal being in intimate contact with the roximate rings of the components-of anot 1er active metal and the product of the periphery and of the height of each contact surface in the proxlmatc rmgs being substantially uniform ace throughout the pile, of a bad heat-conductor f:

filling up the internal annular spaces in the,

superposed couples, a heating pipe for combustible mixture, a bottom of thermoelectrically inactive matcrialclosing the central cavity of the lowermost couple and surrouznling the end of said heating pipe, a cover of tl1erum-electrically inactive material with a hole for closing'the central cavity of the uppermost couple whereby a heating chamber is formed for containing the spent gases and )errnittim their heat. to be utilized, and a cooiing vesse surrounding said superposed couples and insulated therefrom.

9. In a thermoelectric pile, the combination with a plurality of superposed annular couples, each couple formed of two components of dili'erent metals and eachcomponent consisting of two concentric cylindrical rings and arms between them, the rings of each component of one active metal being approximately in the same plane and in intimate contact with the proximate rings of two'neighboring components of another active metal, the product of the periphery and of the height of each contact surface in the proximate rings being substantially uniform throughout the ile, of a bad heat-conductor filling up the internal annular spaces in the superposed couples, a heating pipe for 

